A roof side rail extending longitudinally on left and right sides of a roof of a vehicle is in a closed cross-section structure to enhance rigidity and strength of the vehicle.
PATENT DOCUMENT 1 discloses a roof side rail (12) including a rail inner panel (16) and a rail outer reinforcement (20) which form a closed cross section. A reinforcement patch (40) is disposed in the closed cross section to decrease inward deformation of the roof side rail (12) in a width direction of the vehicle. The reference numbers in the brackets above have been used in PATENT DOCUMENT 1 and are in no way relevant to the reference numbers used in the description of an embodiment of the present application.